Information overload: The brain keeps growing, but there are concerns if it can adapt to digital lifestyle

Can we grow new brain cells as adults? It’s a question that has long divided scientists, but the findings of a new study may have finally settled it. For decades, it was widely believed that the adult human brain was incapable of making new neurons. Scientists thought neurogenesis — the process of making new brain cells — only occurred during childhood and we had to rely on the neurons created then for the rest of our lives. But new research from Sweden published in July has cemented for many experts that our amazing brains keep creating neurons in adulthood. Neuroscientist Jonas Frisén and his team first identified the neural stem cells in the process of becoming new neurons in children’s brains. Then they used artificial intelligence to detect those cells, known as proliferating neural progenitors, in samples of the adult hippocampus — the part of the brain that is crucial for memory and learning. It is hoped the discovery could eventually lead to new treatment for brain diseases. Associate Professor Jennifer Rodger, head of the Perth-based Brain Plasticity Research Lab, said the brain was at the centre of everything we do. “It’s not only what controls all our body and our thoughts and stores our memories, but it’s also affected by the outside world,” she said. “When we experience things, those things also change the brain, so we’re better able to then deal with what’s going on around us. The world influences us through our brain. We influence the world through our brain.” The world has changed immensely in recent years, with the rapid uptake of technology, mass communication, social media and now artificial intelligence. How are our brains affected and cope with the challenges that living in our modern digital world brings? “Our brains adapt on an individual basis, based on our experiences and where we live,” Associate Professor Rodger said. “But from an evolutionary point of view, there isn’t time for the brain to have evolved over 100 years. It takes millions and millions of years for evolution to change things. So, the brain has had to adapt with the capacities that it already has.” Science is beginning to investigate the impact — good and bad — that modern technology is having on our brains and mental health. Professor Harvey believes there are pros and cons to the advent of digital technology and much depends on the nature of the medium and the age at which people start using it. “In the first five or six years of life, I think there are potentially some negatives, not only if the child is using it and not going out to play and mix with others, but also if the parent is on the phone a lot and not communicating with the child, for example,” he said. Professor Harvey warned that digital technology, particularly social media, was certain to affect social wellbeing because of its addictive elements. “A negative impact on social interactions is likely to have a profound impact on brain function at a cognitive level,” he said. Research by the Perth-based Kids Research Institute Australia found the more screen time toddlers were exposed to at home, the less they were engaged in verbal interactions with their parents, which is critical for children’s early language development. Dr Mary Brushe’s study found that three-year-olds exposed to just under three hours of screen time per day – the average for this age group – missed out on more than 1100 adult words, 840 vocalisations and 194 conversational turns per day. An international review of 157 peer-reviewed studies published between 2021 and 2024 said the use of digital devices in childhood influences brain development, cognitive functions and behavioural outcomes in positive and negative ways. “It suggests that while digital media can offer innovative learning experiences, excessive consumption can lead to adverse effects on physical health, cognitive abilities, and language development,” researcher Vicente Javier Clemente-Suárez wrote. It also cited a 2021 study that found children are getting their first phones at an average age of 12.2 years, “marking a critical shift in the timing and intensity of digital engagement”. A University of California study published last month said that any time spent on social media could cause cognitive decline in children. Researchers tracked the social media usage of 6500 children aged nine to 13 over four years and found that both small and large increases resulted in lower scores in reading, memory and vocabulary tests. Butler mum Jamee Brien restricts her three children’s use of screens and digital technology with time limits and to selected times. She said mealtimes were strictly screen-free for “modelling that positive behaviour” to Cooper, 11, Mackenzie, 10, and Chelsea, seven. But Ms Brien said she understood the temptation to give children a screen to occupy them when parents need a break or some time to themselves. “I’m guilty of it. If I want five minutes of silence, I’m like go watch TV or use your iPads,” she said. “But that’s also detrimental, because they’re not talking to anyone, they’re not responding, they’re just watching mindless things or playing mindless games, and it’s not helping their development at all.” Ms Brien said she noticed the impact on her children’s behaviour when their time on their screens was up. “I don’t know what it does to their brain. I think it’s endorphins it gives them. When it’s taken away, there are tantrums, attitude and rolling of the eyes,” she said. Ms Brien said she has learned a lot about the impact of digital technology by taking part in ORIGINS, a longitudinal study of 10,000 WA children being conducted by the Kids Research Institute Australia. German neuroscientist Martin Korte in 2020 wrote that possible effects of digital media use on the human brain, cognition and behaviour were important because of the huge amount of time people spend using it. He cited data from UK communication regulatory agency Ofcom that found 95 per cent of people aged 16 to 24 own a smartphone and check it on average every 12 minutes. Professor Korte said intensive digital media use could be related to impairments in working memory. “Simply seeing a smartphone (not even using it) lowers working memory capacity and leads to decreased performance in cognitive tasks, due to the fact that part of the working memory resources are busy ignoring the phone,” he wrote in Dialogues in Clinical Neuroscience. Professor Korte also explained how research has showed that repetitive use of touchscreens can change the brain’s processing response in the thumb and fingertips within days and warned this could be at the expense of other motor skills. Concerns have been raised that our increasing reliance on technology is impairing our cognitive abilities because we spend so much time passively watching screens or “offloading” thinking to digital devices. Some scientists have warned that “digital dementia” caused by excessive screen time will increase the risk of Alzheimer’s disease and other forms of dementia among Generation Z, those born between 1997 and 2012. But an analysis of 57 studies involving 411,430 adults published in the US in April this year found that greater use of digital technologies was associated with a reduced risk of cognitive decline. Researchers at Melbourne’s Swinburne University recorded the brain activity of 18- to 25-year-olds during different forms of screen use and found that television and gaming were associated with increased focus, while social media was associated with decreased focus. And they they found it only took three minutes of exposure to a phone screen for the young adults to experience changes in mood, tension, focus and happiness. “Almost everyone owns a smart phone which they use for at least three hours a day for entertainment. Mood disorders are increasing in prevalence worldwide and we shouldn’t rule out the possibility that phones are a contributor,” lead researcher Alexandra Gaillard said. Professor Harvey said digital interactions, especially text-based platforms, were not equal to face-to-face interaction because the stress and intonation of speech was missing, and as much as 95 per cent of our communication is non-verbal, such as gesture and facial expression. “Each new technology is reducing the amount of information transfer and losing, I think from an evolutionary context, a huge amount of information that was important,” he said. Many of us will relate to the feeling of “information overload”. A 2023 review by Miriam Arnold, an assistant professor at the University of Groningen, said the digitalisation of work and home life has led to an “information society” in which we can conveniently access diverse information, as well as passively receive a huge amount of information and messages. “Currently, the amount of information that is created every two days is roughly equivalent to the amount of information that was created between the beginning of human civilisation and the year 2003,” the German authors wrote in a paper published in Frontiers in Psychology. This has led to an excessive amount of information, which makes it hard for us to assess the quality of it, often causing stress, burnout and other health problems. Professor Rodger said the brain can filter out the unimportant, but we have discovered ways to trick the brain into paying attention to everything. “Whether through large fonts or colours or words or moving things, those tricks are tapping into the brain’s ability to determine whether something’s important or not,” she said. “That might be why people feel overwhelmed, because everything’s important.” Artificial intelligence (AI) is seeping into numerous aspects of everyday life; from the search engines we use to browse the internet and large language models (LLMs) that can answer questions and generate text about anything. Doctors are now using digital scribes to record consultations and write notes and letters. AI is even being used in hospitals to monitor the condition of patients. The appeal is obvious with its convenience, speed and ability to carry out so many useful tasks for us. But are there any downsides for our brains and cognition? A new study published by Massachusetts Institute of Technology in June 2025 examined the impact of using a LLM on brain function. They analysed the brain activity of the 54 participants who were split into three groups to write an essay using LLM, a search engine or only their brain. “Over four months, LLM users consistently under-performed at neural, linguistic, and behavioural levels,” Nataliya Kosmyna wrote. Those who used their brain only showed the strongest networks of brain connectivity, while LLM users struggled to accurately quote their own work. The authors said the results raised concerns about the “long-term educational implications of LLM reliance and underscore the need for deeper inquiry into AI’s role in learning”. “If you have to write it yourself and collate the information yourself, you’ve got to remember that better later down the track,” Professor Harvey said. Could neuroplasticity — the brain’s ability to form new neural connections to adapt to learning or new experiences — be increasing to cope with all these changes? Professor Rodgers said it wasn’t possible to know because the technological advances to enable us to measure neuroplasticity only came about around 30 years ago. “We know a lot about the brain’s anatomy and connectivity, but there’s a huge amount we still don’t know about cellular impact,” she said. Professor Rodgers believes that – as with the acquisition of language which began some 70,000 years ago and followed by the learning of writing – our brains will be able to adapt. “I think if we can find a way to inform people of how to make the most of the technologies and the things that are overwhelming in many cases, I think our brains will be able to adapt to that,” she said.